//生成guid
function newGuid()
{
    var guid = "";
    for (var i = 1; i <= 32; i++){
      var n = Math.floor(Math.random()*16.0).toString(16);
       guid +=    n;
      if((i==8)||(i==12)||(i==16)||(i==20))
         guid += "-";
     }
    return guid;    
}